slow acceleration

[dirtbag]

Hi guys, just got my first gn its an 87 with 72000 miles. stock no mods(yet) just wondering when you hit the gas should the tires break loose, or is it a slow accel to 15-20 mph. mine is slow to accel from stop. other than that this thing is freakin great.thanks for any info

 

[JDSfastGN]

semi normal -(turbo lag) but it should be pretty quick to spool with it being stock. Do a complete tune up (there is a spring cleaning to follow on www.gnttype.org) This should help a lot, but chances are the stock manifolds have cracks in them slowing spool up quite a bit. If not possibly the stall converter was replaced at once point and its not as good as the original D5?

 

[dirtbag]

manifolds seem ok. checked for leaks didnt really hear any,but ill take a closer look.did the whole spring cleaning car runs better than when i bought it,alot smoother.but its just the off the line thing that has me thinking.i love this car should hav got one years ago. and you guys rule

 

[UNGN]

manifolds seem ok. checked for leaks didnt really hear any,but ill take a closer look.did the whole spring cleaning car runs better than when i bought it,alot smoother.but its just the off the line thing that has me thinking.i love this car should hav got one years ago. and you guys rule

Look close at the driver side manifold with a flashlight. If it doesn't appear to have been re-welded, it's probably cracked.

The other place to check is the turbo to passenger header flange. Since our cars have gone through multiple owners, they have also gone from stock to modified, to back to stock many times. The header flange will warp to a turbo, but when you bolt on another turbo (or even the original stocker) there may be a gap. Even a tiny gap is too large.

 

[Blazer406]

Hi guys, just got my first gn its an 87 with 72000 miles. stock no mods(yet) just wondering when you hit the gas should the tires break loose, or is it a slow accel to 15-20 mph. mine is slow to accel from stop. other than that this thing is freakin great.thanks for any info

Don't know if you know this... but I will chime in a little.....

For it to accelerate very quickly from a stop.... you need to brake-build boost. You mash the brake pedal hard..... start giving it some gas..... boost will start to build..... when it gets to 1-2 psi (on real street tires).... let off the brake.... and floor it. It will jump..... You can experiment with how much boost you can build w/o frying the tires....before you launch. Even in stock form... it will roast the street tires if you build too much boost before you let off the brake.... This takes some time to learn how to finesse it for the best launch.

I don't know what your plans are.... but you should be able to get some 12's out of it with some bolt-ons. Need a good scan tool too..... probably should be the first thing you buy..... and as others have said.... do the spring cleaning stuff per gnttype.org's article.

HTH

 

[dirtbag]

just borrowed a actron scantool from a buddy tonite.(dont think hes going to get it back, he he)im just learning the how to use it,should help in getting to know my ride.will check manifold closely and see whats up. have any you guys delt with poston buick? just got there catalog today and i started thinking about upgrades already. any comments about there ultrachip and 3 inch downpipe? thanks again!

 

[UNGN]

just borrowed a actron scantool from a buddy tonite.(dont think hes going to get it back, he he)im just learning the how to use it,should help in getting to know my ride.will check manifold closely and see whats up. have any you guys delt with poston buick? just got there catalog today and i started thinking about upgrades already. any comments about there ultrachip and 3 inch downpipe? thanks again!

Before a 3" downpipe, make sure you have a good flowing exhaust. 2.5" duals with straight thru mufflers like ultraflows will give more performance than a 3" downpipe. I picked up about .4 seconds with an exhaust, but only .05-.1 from a downpipe (In the high 11's).

 

[matt87gn]

A possibility.. your wastegate may be only giving you around 10-12 lbs boost. I had picked up a car one time that was only pushing 8 lbs; I cranked it up a bit and made a huge difference. You need to get a boost gauge and turn it up a couple lbs and should notice a difference if that's the case.

 

[DOUNVME]

I felt the same way when I first drove my car. Drove 200 miles home in it. Was a beast on the open highway. The wife's V8 Lincoln LS was no prob. Once I got home and checked everything over and verified the receipts, I learned how to drive it. Now it is a BLAST!!!

 

[dirtbag]

guess ill start with boost gauge and look into exhaust. looks like the beginning of a beautiful relationship